The present invention relates to an improved radio frequency identification (RFID) proximity reader antenna used for reading preprogrammed security access cards.
Security access cards are often used as keys to gain entry into or out of buildings, parking garages or the like. Security access cards and readers offer greater security over traditional tumbler locks because the card code cannot be readily copied. Thus, unauthorized use using copied cards is greatly reduced. Furthermore, because the card reader is attached to a host computer, the code on the security access card can be saved in the computer's memory, keeping tally of when each user entered or exited through the secured door or gate.
Traditionally, security access cards were inserted or swiped through a card reader. The card reader would then "read" the code on the card, transmit the code signal to a host computer, and subsequently unlock or open the associated door or gate. However, insert type card readers, as well as the traditional key and tumbler lock systems have several disadvantages. Firstly, the insert and swipe type cards must be inserted into or swiped along the reader. Thus, a user must stop, find their card, remove it from their person or belongings, and then insert it or swipe it through the reader. This process is more time consuming, both for the user inserting the card, as well as subsequent users waiting to insert their own cards. Second, the slot for inserting the security access card on the card reader can be vandalized with liquids, grease, chewing gum, etc., thus preventing the card reader from being used. Third, insert card readers can misread the security access card if the insert card is put into the reader upside down or backwards. Swipe type access cards must be swiped with a precise motion to make sure the entire coded portion of the card is passed by the reader head. If the swipe type card is picked up or lifted too soon, a misread of the code may occur.
Solutions to the above problems have been developed with the advent of radio frequency identification proximity sensor cards and access control readers, i.e. readers. RFID proximity cards allow a user to simply pass the security access card in front of the reader from a distance of a few inches up to several feet away. Because there are no slots to insert the card into, vandalism of the card reader is diminished. Furthermore, misreads of the access card are eliminated, regardless of how the card is presented to the reader. Known proximity readers contain, for example, a magnetic coil which energizes an associated proximity access card. The proximity access card contains a microchip precoded with data. The energy from the reader activates the microchip, which in turn magnetically, electrically or electromagnetically sends the precoded data back to the reader and attached host computer for verification. If the code is verified, the door or gate is subsequently unlocked or opened. An LED signal and/or audio tone may be activated to let the user know the code was verified.
Due to technological constraints, known proximity readers have been constrained to relatively large housings, making them more aesthetically objectionable. Of course, placement of the proximity reader is also limited to areas capable of accommodating the housing.